Zobrazeno 1 - 10
of 14
pro vyhledávání: '"Debottam Nandi"'
Autor:
Debottam Nandi
Publikováno v:
Physics Letters B, Vol 809, Iss , Pp 135695- (2020)
We construct a class of viable bouncing models that are conformally related to cosmological inflation. There are three main difficulties in constructing such a model: (i) A stable (attractor) solution, (ii) A non-singular bounce, and (iii) to bypass
Externí odkaz:
https://doaj.org/article/be21fa7514cf4967bbc0e5bf6ab8b454
Autor:
Debottam Nandi
Publikováno v:
Universe, Vol 7, Iss 3, p 62 (2021)
The main difficulties in constructing a viable early Universe bouncing model are: to bypass the observational and theoretical no-go theorem, to construct a stable non-singular bouncing phase, and perhaps, the major concern of it is to construct a sta
Externí odkaz:
https://doaj.org/article/be09c91dced344ac9f6bc3becc6871e6
At astrophysical and cosmological scales, there is a detectable amount of magnetic field. There are several probable origins for this observed magnetic field, including the possibility of its origin in the early Universe. There are several models for
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0884d4981e6fc44c56171ef85591382c
Autor:
Debottam Nandi
Publikováno v:
Journal of Cosmology and Astroparticle Physics. 2021:039
The simplest model of primordial magnetogenesis can provide scale-invariant magnetic fields that can explain the present abundances of it in the cosmic scales. Two kinds of solutions of the coupling function can lead to such phenomena and both of the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6aeaf6783cb713501be7b29243032977
https://doi.org/10.1088/1475-7516/2021/08/039
https://doi.org/10.1088/1475-7516/2021/08/039
Autor:
Debottam Nandi
Publikováno v:
Universe
Volume 7
Issue 3
Universe, Vol 7, Iss 62, p 62 (2021)
Volume 7
Issue 3
Universe, Vol 7, Iss 62, p 62 (2021)
The main difficulties in constructing a viable early Universe bouncing model are: to bypass the observational and theoretical \emph{no-go} theorem, to construct a stable non-singular bouncing phase and perhaps, the major concern of it is to construct
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f4468303015bb720f5158b72c8c56026
Autor:
Debottam Nandi, L. Sriramkumar
An important property of the three-point functions generated in the early universe is the so-called consistency condition. According to the condition, in the squeezed limit wherein the wavenumber of one of the three modes (constituting the triangular
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c27625a5049bfc6f28632758d2c72862
http://arxiv.org/abs/1904.13254
http://arxiv.org/abs/1904.13254
Autor:
Debottam Nandi
Dynamics in conformally connected frames are often referred to as 'equivalent'. In the context of cosmology, while the perturbations remain invariant for a single scalar field model, the background equations differ and therefore the dynamics. However
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d447d623bb05a281a3973ed4ad4ae8fc
Autor:
Debottam Nandi
Contracting Universe (including bouncing models) solution generally depends on the initial conditions and hence possesses an extreme fine-tuning problem. In order to probe the stability of those solutions, in this work, we consider the Brans-Dicke th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5e29bceb45cf285c92fe74afa6b4e351
http://arxiv.org/abs/1811.09625
http://arxiv.org/abs/1811.09625
Autor:
Rahul Kothari, Debottam Nandi
Publikováno v:
Journal of Cosmology and Astroparticle Physics. 2019:026-026
Primordial Gravitational waves leave polarization imprints on the Cosmic Microwave Background (CMB). In this article, we investigate polarization bispectrum, which is also referred to as the B-mode auto bispectrum, due to a matter bounce Universe. Fo
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c268896dddf5dad9017c4dbb0d8e21fa
https://doi.org/10.1088/1475-7516/2019/10/026
https://doi.org/10.1088/1475-7516/2019/10/026
Autor:
S. Shankaranarayanan, Debottam Nandi
In this work, we present a consistent Hamiltonian analysis of cosmological perturbations for generalized non-canonical scalar fields. In order to do so, we introduce a new phase-space variable that is uniquely defined for different non-canonical scal
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e2b5000fcd1081ffec1956926e107986